Carlsbad bridge nearly finished, others need replacement

CARLSBAD -- A $5.6 million replacement of the railroad bridge
spanning Agua Hedionda Lagoon is nearly finished, but a
transportation official Friday said several other bridges along the
coastal railway need work.

Some of the bridges are decades old and many are subject to the
corrosive effects of sea breezes and brackish lagoon water.
Heavier-than-ever train traffic also is causing wear and tear,
officials say.

In addition to those factors, the 60-year-old Agua Hedionda
bridge has been weakened by the marine borer, or shipworm, that
feeds on the timber pilings.

"They literally eat the core, and we are left with a ring for a
pile," said Tom Lichterman, the district's director of rail
services.

The North County Transit District owns 34 bridges along its
railway, which runs from the Orange County line to Santa Fe Depot
in San Diego. Twenty-three of the bridges are aging timber
trestles, and some of those date to 1919.

Design work has begun to replace the bridge spanning Santa
Margarita River on Camp Pendleton, and transportation planners say
they have identified funding to begin designing a replacement
bridge over the San Dieguito River in Del Mar.

Sometime this fall, the transit district will hire a consultant
to analyze the strength of seven other bridges, including one that
crosses San Elijo Lagoon in Encinitas, spokesman Tom Kelleher said
Friday.

"What we see is there has been an increased deterioration of the
existing bridges," Kelleher said. "They're just very old."

Later this month, the transit district will own one fewer wooden
bridge.

On the weekend of Sept. 23, railroad workers will sever the
tracks on either side of the old Agua Hedionda bridge and connect
them to rails crossing the new, 196-foot-long bridge.

The old bridge is supported by more than 50 creosote-treated
pilings, many of which are driven into a channel of the lagoon. The
new bridge sits atop two concrete columns that straddle the
channel.

On top of the columns are 100-foot-long cross-members of precast
concrete that weigh 130 tons each, said Mark Goldberg, field
engineer for FCI Constructors, who works from a mobile office near
the bridge.

Once the new bridge is in service, a subcontractor for FCI will
remove the old one, Goldberg said. He said he expects the job to be
finished in early October.

Design work is 90 percent finished for a replacement bridge at
Santa Margarita River on Camp Pendleton, said Leslie Blanda of the
San Diego Association of Governments, the agency responsible for
planning the job.

Planners are designing the new bridge with two sets of tracks
that will allow trains to pass each other. The existing bridge has
one set of tracks.

In addition to the bridge replacement, the $42.7 million job
includes the addition of nearly one mile of track to create a
4.5-mile-long section of double-tracked line near the district's
train yard on Camp Pendleton.

The project also includes straightening some sections of track
nearby at the Fallbrook Junction, Blanda said.

Blanda, who also is overseeing the planned replacement of the
San Dieguito Lagoon railroad trestle, said $850,000 in state
transportation funds would become available to begin design work
and environmental studies next summer.